1. Field of the Invention
This invention relates to a retail checkout system, and more particularly, to a method of updating price look up (PLU) files in a point of sale terminal of a retail establishment.
2. Description of Related Art
The use of Universal Product Code (UPC) labels or bar codes to identify purchased articles or merchandise items in a checkout system of a retail establishment has become quite common. The typical checkout system includes a point of sale (POS) terminal having an optical scanner for scanning the bar codes on the purchased articles or items. The scanner is usually located in a checkout counter, but it may be hand-held by an operator of the terminal. In either case, when a customer purchases articles, he brings them to the checkout counter. The operator at the checkout counter then uses the optical scanner to scan the bar code affixed to the articles. The optical scanner generates electrical data signals corresponding to the bar code on the label. The data signals are typically used by the POS terminal to "look up" or locate a price for the article in a price look up (PLU) table or file stored in the POS terminal or stored in a remote in-store processor which is coupled to the POS terminal. The price located for the article is then transmitted to the POS terminal where it can be printed on a receipt or like document and/or displayed on a display coupled to the POS terminal.
In checkout systems which utilize bar codes, it is necessary to register information (such as the article name, unit price, and/or class code) for each article in the inventory of the retail establishment. It is not uncommon that the information corresponding to some articles will not be registered in the PLU file at the time the article is purchased because the article is a new arrival, because of a large volume of articles in the inventory of the retail establishment, or because the article was mis-registered in the PLU file due to human error. When information corresponding to the article is not-yet-registered or is mis-registered in the PLU file (hereinafter collectively referred to as "not-yet-registered"), the not-yet-registered information has typically been corrected or saved by any one of the following methods. First, an operator of the POS terminal can register the information for that article on the spot using the POS terminal (for the immediate transaction only), and he can then add the article information to the PLU file later. Secondly, if information is not in the PLU file of the POS terminal, but is stored in the PLU file of a connected remote in-store processor, the operator can use the POS terminal to inquire or poll the PLU file in the in-store processor for information corresponding to the article being purchased. If information corresponding to the article is stored in the PLU file in the in-store processor, the information will be transmitted from the processor to the POS terminal, thereby updating the POS terminal. Thirdly, when a not-yet-registered article is encountered, the operator obtains information for the article by manually referring to a printed look-up catalogue. The POS terminal stores the information for articles encountered during the business day on a floppy disk. The floppy disk is then used to update the PLU file at the end of the business day.
The above three methods have the following drawbacks. In the first method, the customer who purchased the article has to wait until the operator registers the article in the POS terminal. This is an obstacle to efficiency. If the operator is inexperienced, there is also a danger of registering an incorrect price for the article. In the second method, the checkout system having the in-store processor is large in scale and the information on the not-yet-registered article is not always stored in the PLU file in the in-store processor. In the third method, the information for the not-yet-registered article which is stored on the floppy disk is not set and registered until the end of that business day.